Heating and air cooling systems which employ gas turbines are known and have been used principally with air temperature control systems for jet aircraft. In such systems, air is normally taken from the ambient and pumped into a bifurcated conduit or line. One section of the bifurcated line feeds the combustion chamber of the gas turbine whereat it is mixed with fuel and ignited to provide the reaction phenomenon or jet action to drive the aircraft. The other path of the bifurcated line takes the ambient air (which has been raised to some higher pressure than its ambient pressure) after it has been pumped aboard, and directs it through a heat exchanger to the cabin of the aircraft to warm the cabin. In some versions of the system, see, for instance, U.S. Pat. No. 2,618,470, this air is used to drive a one-stage pump and the pump is usually coupled to an electrical generator or some other load that needs mechanical power. The pump, of course, is driven and the air is cooled somewhat during this operation. However, it should be understood that the principal source of cooling the air for the aircraft system is the outside atmosphere with its low temperature. When an aircraft is flying at 20,000 feet or more, the ambient air temperature is very cold, so providing a source of cool air is not a major problem.
In these aircraft systems the main purpose of the equipment is to extract heat from the turbine exhaust and use that heat to warm the cabin, prevent icing, and do some additional work through such devices as the single stage pump mentioned above. It should be borne in mind that finding a source of heat is a relatively simple matter and is a by-product of a system which is already present in a jet aircraft because the exhaust temperatures of the jet engines are about 1,000.degree. F. Further, as part of the background, it should be understood that in an airplane system, cost is not a controlling factor and since both the source of heat and the source of cold temperatures are readily available, providing such sources does not add to the cost of the air temperature control system.